Guides and instruments for improving accuracy of glenoid implant placement

Abstract

A method is disclosed for making a glenoid guide that includes obtaining scapula surface profile information of a specific patient, providing a manufacturing plan for making the glenoid guide having at least one patient specific contact surface configured to contact a portion of the glenoid rim or glenoid surface and for making the guide having a rotation control feature forming member, and adapting the manufacturing plan to specify the location of the rotation control forming feature relative to a portion of the glenoid determined to benefit from augmentation based on the surface profile information.

We claim: 
     
         1 . A method, comprising:
 placing a patient-specific glenoid guide having at least one patient-specific bone contact surface on a surface of a scapula of a patient such that the at least one patient-specific bone contact surface is in contact with a corresponding surface of the scapula;   establishing, using the patient-specific glenoid guide, a central guide feature extending from a central surface of a glenoid of the scapula;   establishing, using the patient-specific glenoid guide, a peripheral guide feature located in or on the scapula peripheral to the central surface of the glenoid identified by the central guide feature;   placing, using a baseplate inserter and with reference to the peripheral guide feature, a baseplate of a reverse glenoid prosthesis in contact with the glenoid of the scapula such that a wedge portion of the baseplate of the reverse glenoid component is aligned with a surface of the glenoid to be augmented according to a pre-operative surgical plan.   
     
     
         2 . The method of  claim 1 , wherein the wedge portion of the glenoid prosthesis is patient specific. 
     
     
         3 . The method of  claim 2 , wherein the wedge portion of the glenoid prosthesis is sized and configured to fill a portion of the glenoid based on pre-operative imaging of the glenoid. 
     
     
         4 . The method of  claim 1 , further comprising:
 coupling a reaming guide to a reamer;   after coupling the reaming guide to the reamer, advancing the reaming guide over or into a proximal portion of the peripheral guide feature;   advancing the reamer to the glenoid surface with reference to the central guide feature and to the peripheral guide feature;   reaming the glenoid surface with continued reference to the central guide feature and to the peripheral guide feature.   
     
     
         5 . The method of  claim 4 , wherein the peripheral guide feature comprises an aperture formed in a portion of the scapula superior to the central glenoid surface. 
     
     
         6 . The method of  claim 5 , wherein establishing, using the patient-specific glenoid guide, the peripheral guide feature includes inserting a peg into the aperture formed in the portion of the scapula superior to the central glenoid surface. 
     
     
         7 . The method of  claim 6 , further comprising:
 inserting a projection of a rigid body of the reaming guide into an aperture in a proximal portion of the peg.   
     
     
         8 . The method of  claim 7 , further comprising:
 aligning a proximal projection of the peg with a guide channel of the projection of the rigid body while inserting the projection of the rigid body into the aperture in the proximal portion of the peg.   
     
     
         9 . The method of  claim 8 , wherein the proximal projection and the guide channel are on the superior portion of the peg and rigid body respectively. 
     
     
         10 . The method of  claim 4 , wherein the peripheral guide feature comprises a pin projecting laterally from the surface of the scapula. 
     
     
         11 . The method of  claim 10 , wherein the reaming guide comprises a rigid body comprising a projection having a distal opening, a proximal opening, and an elongate body disposed therebetween, the elongate body enclosing a guide lumen along a length thereof between the distal opening and the proximal opening. 
     
     
         12 . The method of  claim 11 , further comprising:
 advancing the distal opening over a proximal end of a guide pin after coupling the reaming guide to the reamer.   
     
     
         13 . The method of  claim 11 , further comprising:
 ceasing reaming upon contact between a distal face of the elongate body of the reaming guide and the surface of the scapula peripheral to the central surface of the glenoid.   
     
     
         14 . The method of  claim 1 , wherein the baseplate inserter includes:
 an elongate body comprising a first end, a second end, and a glenoid implant component retention feature disposed on the first end, the glenoid implant component retention feature configured to retain the baseplate of the reverse glenoid prosthesis; and   a rotation guide configured to engage the peripheral guide feature.   
     
     
         15 . The method of  claim 1 , wherein the baseplate inserter includes:
 an outer shell extending from a first end to a second end, the first end of the outer shell including a glenoid implant component retention feature configured to engage and retain the baseplate of the reverse glenoid prosthesis;   an inner shell disposed in the outer shell, the inner shell configured to move between a first position within the outer shell and a second position within the outer shell; and   a rotation guide configured to engage the peripheral guide feature.   
     
     
         16 . The method of  claim 15 , wherein placing, using the baseplate inserter and with reference to the peripheral guide feature, includes:
 moving the inner shell of the baseplate inserter in a first direction relative to the outer shell of the baseplate inserter to cause the glenoid implant component retention feature to engage and retain the baseplate of the reverse glenoid prosthesis;   aligning the rotation guide with the peripheral guide feature; and   advancing the baseplate of the reverse glenoid component into the glenoid.   
     
     
         17 . A method of making a glenoid guide, the method comprising:
 obtaining scapula surface profile information of a specific patient;   providing a manufacturing plan for making the glenoid guide having at least one patient specific contact surface configured to contact a portion of the glenoid rim or glenoid surface and for making the guide having a rotation control feature forming member; and   adapting the manufacturing plan to specify the location of the rotation control forming feature relative to a portion of the glenoid determined to benefit from augmentation based on the surface profile information.   
     
     
         18 . The method of  claim 17 , further comprising:
 manufacturing the glenoid guide using additive manufacturing to form at least the patient specific contact surface and the rotation control forming feature.   
     
     
         19 . The method of  claim 17 , wherein adapting the manufacturing plan to specify the location comprises specifying that the position of the rotation control forming feature is opposite of the portion of the glenoid determined to benefit from augmentation. 
     
     
         20 . The method of  claim 19 , wherein the position of the rotation control forming feature is 180 degrees offset from the portion of the glenoid determined to benefit from augmentation.